The backbone of vehicles such as automobiles, light trucks, vans, and recreation vehicles is a structure known in the automotive industry as a body-in-white. The body-in-white (BIW) is the skeletal structure or shell to which various subsystems are subsequently attached. These subsystems may include an engine and drive train, suspension and wheels, interior trim and seating components, and exterior ornamentation.
In the BIW of many modern vehicles, numerous structural and non-structural panels are joined together, to form a self-supporting, unitary, structural shell known as a uni-body. The uni-body eliminates the need for having a separate structural frame, as is required in traditional body-on-frame construction.
Uni-body construction is well suited to the BIW of a vehicle having a hard-top roof structure, such as a sedan or a coupe. In such a vehicle, the roof provides a substantial portion of the structural strength and stiffness of the uni-body that is available for joining the engine and suspension components at the front of the vehicle to the rear suspension.
In vehicles such as convertibles or roadsters, however, having a soft-top or no top, or in vehicles where a significant portion of the top is removable, the remaining portion of the uni-body must include sufficient additional structure to provide a uni-body that is strong enough and stiff enough to withstand the static and dynamic loads incident with operation of the vehicle. In the BIW of such vehicles, the number and material gage of the individual components of the uni-body must often be more than doubled in certain critical areas to achieve the required structural strength and stiffness of the uni-body. Adding these components, and increasing the material thickness, undesirably increases the cost, weight and complexity of the uni-body BIW of the vehicle, and can require that the assembly procedures on an assembly line be altered considerably for accommodating vehicles without hard-top roof structures.
What is needed is an improved architecture and method for producing a uni-body, body-in-white, providing the additional structural strength and stiffness required in certain types of vehicles, such as convertibles, roadsters, and vehicles where a significant portion of an otherwise hard-top roof are removable, that can be assembled on a conventional uni-body assembly line with common manufacturing techniques.